No abstract

Fruticulture is a prominent component of Brazilian agriculture. Studies have shown that climatic variability and its impact on the physiological development of plant species are fundamental for planning the agricultural calendar, resource conservation, and sustainable management of production. In this context, one of the first criterion for planting a crop is agroclimatic zoning, since it provides information on climate-related risks and aids decision-making and agricultural planning. The objective of this study was to carry out climatic risk zoning for avocado (Persea americana Mill.) in the basin of Paraná River III, Paraná State, Brazil. Meteorological data from 43 stations, from 1976 to 2018, were used. The climatic risk analysis was based on the requirements of the avocado for precipitation, water balance, average annual temperature, and frost tolerance. Statistical and geoprocessing techniques ensured full regional coverage of data and contributed to decision-making. The results identified favorable climatic conditions for all climatic variables in the western part of the river basin. Despite water deficits in some months, rainfall and water balance were not restrictive for avocado production in the region. Avocado tree cultivation is not recommended in the eastern part of the basin, where there is a considerable risk of frost.

To improve soil health and to aid in climate change mitigation, the quantity of soil organic matter (SOM) should be maintained or increased over the long run. In doing so, not only the total quantity of SOC but also the stability of SOC must be considered. Stability of SOC increases as a function of resistance to microbial decomposition or microbial substrate use efficiency through chemical, biological, and physical mechanisms including humification, hydrophobic moieties, molecular diversity, and formation of macroaggregates. One of the mechanisms that enhance stability confers changes in the distribution of C functional groups of SOM. To better understand and quantify how these changes are influenced by agricultural management practices, we collected 670 pairwise data from the body of literature that has evaluated changes in the distribution of C functional groups of SOM measured by solid-state 13C NMR spectroscopy. The types of agricultural managements discussed herein include (1) fertilization, (2) tillage, (3) crop rotation, (4) grazing, and (5) liming practices. Our meta-analyses show that these practices modify the distribution of C functional groups of SOM. Fertilization practices were associated with increased O-alkyl groups. Tillage resulted in increases in the SOC consisted of aromatic and carbonyl groups. Crop rotations, especially legume-based rotations, were found to increase the proportion of aromatic groups. Although there are fewer publications on tillage and crop rotation than on fertilization practices, the distribution of C functional groups may be more influenced by crop rotation and tillage practices than fertilization management—and should be a focus of future research.

ResumoO objetivo do trabalho foi realizar o zoneamento agroclimático de café robusta (Coffea canephora Pierre ex Froehner) no estado do Paraná e verificar as alterações causadas neste, pelo incremento de temperatura, provocado pelo aquecimento global, conforme prognósticos para os próximos 100 anos divulgados pelo IPCC (Intergovernmental Panel on Climate Change). Uma alternativa para manter a produção cafeeira no estado do Paraná poderá ser a introdução do café robusta, originário da África, adaptado a regiões com temperatura média anual entre 22 e 26 o C. Foi utilizado o banco de dados climáticos históricos do IAPAR (Instituto Agronômico do Paraná) e consideradas aptas ao cultivo as regiões que se enquadraram dentro dos seguintes critérios: risco anual de ocorrência de geadas inferior a 25%, temperatura média anual entre 22 e 26°C e deficiência hídrica anual inferior a 150 mm. Os mapas foram gerados sobre a base Shuttle Radar Topography Mission (SRTM) e cruzados no ambiente de Sistema de Informação Geográfica (SIG), gerando os mapas do zoneamento agroclimático do Coffea canephora para o clima atual e para os cenários de mudanças climáticas com o acréscimo de 1,8 e 4 o C na temperatura média. O zoneamento para o clima atual indicou que partes das regiões noroeste e oeste são aptas ao cultivo. Sob cenários de mudanças climáticas, considerando o regime de precipitação inalterado, a área apta ao cultivo se amplia, justificando estudos sobre esta espécie no estado do Paraná. Palavras-chave: Coffea canephora, aquecimento global, temperatura AbstractThe aim of the study was the agroclimatic zoning of robusta coffee (Coffea canephora Pierre ex Froehner) in the state of Paraná, and to verify changes caused by temperature rise related to global warming, as predictions for the next 100 years reported by the IPCC (Intergovernmental Panel on Climate Change). An alternative to keep coffee production in the state of Paraná will be the introduction of robusta coffee, original from Africa, adapted to areas with annual mean temperatures between 22 and 26 o C. We used the historical weather database from IAPAR (Agronomic Institute of Paraná) and considered as apt for cropping the areas within the following conditions: risk of annual frost lower than 25% of probability, annual mean temperature between 22 and 26 °C, and annual water deficiency below 150 mm. The spatial analyzes were based on the Shuttle Radar Topography Mission (SRTM) and crossed into the environment of a Geographic Information System (GIS), generating maps of the agroclimatic zoning of Coffea canephora for the current climate and scenarios of climate change with

RESUMO-O abacateiro apresenta grande diversidade de tolerância a baixas temperaturas devido às suas regiões de origem. As raças mexicanas são mais tolerantes, as raças antilhanas são mais sensíveis e as guatemalenses têm comportamento intermediário. Neste trabalho o zoneamento de riscos climáticos fundamentou-se na severidade das geadas, por meio da análise de séries históricas de temperaturas mínimas em um ambiente de Sistema de Informação Geográfica. Foram identificadas quatro zonas distintas de risco, caracterizando geadas muito fortes e frequentes, onde não se recomenda o cultivo; geadas fortes, onde somente a cultivar Fuerte é recomendada; geadas moderadas, onde somente as cultivares Primavera e Margarida não são recomendadas, e uma zona de baixo risco, no norte e oeste do Paraná, onde todas as cultivares são indicadas. As diversidades de climas no Paraná e as exigências térmicas das cultivares possibilitam a colheita em grande parte do ano por meio da combinação de diferentes cultivares e regiões de plantio. Termos para indexação Persea americana, risco de geadas, graus-dia, épocas de colheita. AGROCLIMATIC ZONING FOR AVOCADO CULTURE IN THE STATE OF PARANAABSTRACT -Avocado cultivars have a great diversity of tolerance to low temperatures due to their regions of origin. The Mexican breeds are more tolerant, the West Indian breeds are more sensitive and the Guatemalan breeds have intermediate behavior. In this study, the zoning of climate risks in the state of Parana was based on the severity of frost, through the analysis of historical series of minimum temperatures in a Geographic Information System. We identified four distinct areas of risk, namely, a zone with very strong and frequent frosts where cultivation is not recommended, a zone where frosts are strong and only the cultivar Fuerte is recommended, a zone with moderate frosts and only Primavera and Margarida cultivars are not recommended, and a zone of low risk in the north and west of Paraná, where all cultivars are indicated. The diversity of climates in Paraná and thermal requirements of the cultivars allow the harvest during most of the year through a combination of different cultivars and growing regions.